Interzooecial Communication in Flustridas. By A. W. Waters. 283 
Rosette Plates. 
Lamina. 
Avicu- 
laria. 
Ovicells. 
Spines. 
Ten- 
tacles. 
Figured. 
Distal. 
Lateral. 
Flustra securi- 
(!) 1* * * § 
(r) 6-8 
2 
semi- 
im- 
? 
PI. VII. 26 
frons Pallas 
circular 
mersed. 
F. papyrea 
(0 1 
(0 2 
1 
0 
unknown 
0 
Pallas 
F. nobilis Hincks 
00 1 
00 2 
1 
minute 
unknown 
nume- 
PI. VII. 
' semic. 
rous 
! 10, 11 
F. pisciformis 
(0 1 
(0 2 
1 
0 
imm. 
0 
24 (B) 
PI. VII. 
Busk 
12, 13 
F. biseriata Busk 
(I) 1 
(0 4 
2 
0 
imm. 
0 
19 
PI. VII. 
6 -9. 22 
F. dissimilis 
2? 
(*) 4 
1 
trian- 
raised 
0-1 or 
PI. VII. 17 
Busk 
gular 
1-1 
F. serrulata Busk 
2 
2 
1 & 2 f 
0 
imm. 
0 
22 
PI. VII. 
1-3 
F. membranaceo- 
([) 3 
(') 6 
1 
semic. 
imm. 
0 
16 (V) 
truncata Smitt 
F. Barleei Busk 
(i) 3 
(r) 6-8 
2 
semic. 
imm. 
0 
PI. VIII. 15 
F. tenella Hincks 
(r) 4 
(i) 10-12 
2 
triang. 
imm. 
1-1 
pi. vir. 
24, 25 
PI. VIII 14 
F. oblonga Waters 
4 
6 
1 
triang. 
lunknown 
0 
PI. VIII. 
12, 13 
F. papyracea 
(i) 6 
(r) 10 
2 j 
o 
imm. 
1-1 
Ellis 
F. cribriformis 
6 
16-18 
1 
o 
imm. 
0 
PI. VII. 
Busk 
. 31. 32 
F, denticulata 
(r) 6 
(i) 10-12 
2 
triang.J 
imm. 
various 
PI. VIII. 
Busk 
17. 18 
F. dentigera 
(i) 6 
(i) 10 
2 
0 
imm.§ 
0 
PI. VII. 
Hincks 
33, 34 
F. spinuligera 
(0 6 
(0 16 
2 1| 
triang. 
imm. 
various 
PI. VIII. 
Hincks 
19, 20 
F. cyathiformis 
(i) nume- 
(i) 6 
1 
0 
unknown 
0 
PI. VII. 
MacG. 
rous 
1 
20, 21 
four walls, there is in the bilaminate forms none between the walls 
known as the basal or neural wall ; nor is this confined to Flustra , 
* (i), (s), signify one or several pores in the rosette plate. 
f Levinsen, G. M. R., ‘ Bryozoer fra Kara Havet Dijmphna-Togtets,’ Zool. Bot. 
Udbytte, 1886, p. 316 (12), pi. xxvii. figs. 1, 2. Says serrulata occurs as uni- 
laminate and as bilaminate. In the specimens in my collection from Greenland and 
Bell Island it is bilaminate. 
X As the ovicell occurs in conjunction with the avicularia they are prominent, 
but the ovicell is immersed in the zooecium above it. Hincks, in his description of 
dentigera, says the ovicell of denticulata is not immersed, but sections show them 
distinctly immersed. Busk, when he says in the ‘Challenger’ Report that the 
rosette plates only occur in the bordering zocecia of denticulata, is, of course, 
mistaken. 
§ F. dentigera has a much longer ovicell than that of F. denticulata or F. spinu- 
ligera. 
|| Hincks (Aun. M.N.H., ser. 6, vol. xii. p. 145) says F. spinuligera is unilami- 
nate and F. rhizopora Ort. bilaminate, but this is clearly a slip, and he means the 
opposite. The mandible of F, spinuligera has a much longer beak than that of 
F. denticulata. 
